1. Field of the Invention
The present invention relates to a photographing information setting device, for entering photographing information such as shutter speed and diaphragm aperture, for use in a camera.
2. Related Background Art
For setting photographing information of a camera, such as shutter speed and diaphragm aperture, and entering such information into the control means of the camera, there is already known a method of manually rotating a rotary operation member on which the shutter speeds or diaphragm aperture values are printed, whereby a variable resistor linked with said operation member is rotated and the shutter speed or the diaphragm aperture value is set by reading the resistance of such variable resistor.
However, in order to improve the precision of setting within a limited space of the camera, such method requires a compact variable resistor of a high precision, thus leading to an increased cost. Also technology of a high level is required for mounting the brush, linked with the rotary operation member and contacting a resistance member, so as to achieve a precise sliding motion, thus again leading to an increased cost.
Also there has been developed a method of employing a code board instead of the variable resistor, thereby setting the photographing information in the form of digital signals instead of the change in resistance, but such method inevitably requires a large-sized code board if the amount of information increases, thereby rendering the camera itself bulky.
For this reason there has also been developed, as disclosed in the Japanese Patent Laid-open Application No. 60-118825 and No. 3-32049, a method which employs a rotary operation member, means for detecting the drive direction of the operation member by discriminating the phases of two signals mutually different in phase, and a display unit for displaying the currently set photographing information, and in which the desired photographing information can be set by regulating the set value by the rotation of the operation member while confirming the set value on the display unit.
In this method, since the rotary operation member is separate from the display part of the display unit, the number of rotations of the operation member is not limited and there can be provided a large number of selectable set values. Consequently, there is facilitated the setting of intermediate values, which has been difficult with the information setting device mentioned above.
However, in such photographing information setting device of the camera, since the display unit usually utilizes a liquid crystal display or the like, the displayed information cannot be read unless the power supply of the camera is turned on. Consequently, the power supply of the camera has to be turned on in order to confirm the photographing information, so that the operation of the camera becomes complex.
Also, if the number of selectable set values is increased excessively, the photographer has to rotate the operation member by a number of turns in order to set the desired photographing information, so that the setting of photographing information within a short time becomes difficult.